Earthquakes can cause which secondary hazards?

• A. Mudslides
• B. Mudslides, landslides, and falling rocks/debris
• C. Tsunamis
• D. Groundwater contamination

Answer: (B)

Earthquake shaking destabilizes slopes and loose materials on hillsides, road cuts, and cliff faces. This often leads to mudslides and landslides, where soil, rock, and debris rush downslope, sometimes soaked with water forming a mudslide. Falling rocks and debris from fractured cliffs and rock faces are another common secondary hazard produced by the ground motion. Tsunamis can occur if the quake affects the ocean floor, but that’s limited to coastal or undersea events and isn’t a universal secondary effect of earthquakes. Groundwater contamination isn’t a typical direct outcome of the shaking itself, so it’s not as representative of the common secondary hazards. That broader combination of mudflows, landslides, and rockfalls best captures what earthquakes most often trigger as secondary hazards.